I. Field of the Invention
This invention relates to a turnout unit for railway tracks, and more particularly, this invention relates to a turnout unit which has an improved sliding surface on which a tongue rail slides.
II. Description of the Prior Art
Turnout points are the most important parts of railway tracks from the point of view of track safety and their upkeep is a key item in rail track maintenance.
In general, turnout point construction comprises a tongue rail which slides on a base plate made of steel. In order to ensure smooth sliding of the tongue rail, it is necessary to keep the base plate well lubricated. Thus, it is necessary to periodically apply lubricating oil to the sliding surface of the base plate.
To eliminate this periodical application of lubricating oil, it was proposed in Japanese Utility Model Disclosure (Kokai) Nos. 140507/77 and 125501/84 to embed a solid lubricant in the sliding surface of the base plate.
However, the solid lubricant has an unsatisfactory weatherability and wear resistance. Further, since the solid lubricant is embedded in a copper alloy layer formed on the base plate made of steel, manufacturing of the structure is laborious and costly.